Nature is Resilient: Talk by Sean B Carroll at Bristol’s Festival of Ideas

When it feels like my brain is pounding against my skull, I know that I’m learning something new. Not just new but complex enough to make never before used synapses painfully snap into place . I was listening to Professor Sean B Carroll talk about the ideas that ground his book based on the Serengeti. In a talk that was part of the ongoing Bristol Festival of Ideas, in a series of slides, videos and charts, he took us not just to Tanzania but also to the Yellowstone park in the US (among other places) and then back again to Africa, to Mozambique.

Professor Sean B Carroll

It was head splitting.

Sean B. Carroll is a professor of molecular biology, genetics, and medical genetics at the University of Wisconsin–Madison and with an American accent I’ve never come across in movies or on TV, he explained to us the damage we were doing to the earth. That was my main take away but I’m getting ahead of myself. We looked at a video and pictures of Prof Carroll and his family driving through the Serengeti. A place so breathtaking that I mentally added Serengeti to my bucket list.

Everything in nature is regulated, including your body. And by knowing how the players (e.g molecules) work and the rules of regulation we are able to restore missing players or fix broken links. In all habitats, there is a keystone species which regulates the diversity of the community. A keystone species is a species that when taken out of a habitat or when they aren’t present in sufficient numbers, throws the habitat out of whack. In the Serengeti, wildebeest were the keystone species. But their main killer wasn’t predators or lack of food- it was disease. Rinderpest to be exact. Damn you pesky rinderpest. When the Tanzanians began immunising their cattle, an unintended effect was that the wildebeest became immunised as well. This led to a knock on effect which helped the Serengeti thrive. There were more wildebeest to feed on the grass “natural lawnmowers” which led to the grass being so short that the yearly bush fires didn’t have much fuel to feed on. Because there were less bush fires, the trees were able to grow. With more trees, came more food for giraffes. And so the giraffe population increased. Not just giraffes, there were more butterflies as well.

Wildebeest: Keystone species of the Serengeti

He also spoke about how we’ve decimated the population of big predators like bears, lions, wolves to the detriment of habitats. “Excess mortality imposed by human beings” has been responsible for nature’s the imbalance. For instance, wolves were completely wiped out of Yellowstone and that led to a decline in the number of Aspen trees because there were more elks to feed on them. The elks were frolicking while the big dog wasn’t home. When wolves were reintroduced into Yellowstone, the aspens began to thrive once more. Yes more elks died but yay trees! Not only that, other species like beavers benefited as well, as there was more food in their case, willows to feed off of.

Wolves, more important than we thought

Time and time again, he showed us how when keystone species were taken out of a habitat, it led to a collapse in the ecosystem. It really drove home to me what human beings were doing to the planet. We are truly messing up our animals. Saying this as a person who comes from a country where the only animals we acknowledge are the tasty ones, that’s me saying a lot.

He rounded up the talk with the story of the Gorongosa National Park. It was a thriving park like the Serengeti, with millions of diverse animals, until the Mozambique Civil War hit. A war which lasted from 1981-1994. And for nine of those years, the park was the site of battles between the warring sides. At the end of the war, through poaching, hunting for food, starvation, 95% of the animal population had been wiped out. According to Wikipedia “Surveys counted just 15 buffalo, 5 zebra, 6 lions, 100 hippos, 300 elephants and just a handful of wildebeest.” But a Great White Hope emerged (they always do) and in 2004 the US based Carr Foundation started working with the Mozambique government to restore Gorongosa to its former glory. They reintroduced some species like zebra and wildebeest into the park and they are thriving. Except the lions who don’t play so nicely with newly introduced strange lions from nowhere.

Gorongosa’s story shows us that “nature is resilient and given a chance (habitat protection and time) populations can rebound dramatically.” In many cases, we can reverse the damage we’ve done to ecosystems. All hope is not lost.